Visual search for a circular region perceived as a figure versus as a hole: evidence of the importance of part structure.

To study contour curvature polarity, we compared strictly convex regions (circular figures) with strictly concave regions (circular holes). We tested for an asymmetry between visual searches for concavities and those for convexities. We found that providing a preview of the background benefited search for concavities (holes) more than it did search for convexities (figures) and that for convex figures, nearer targets were responded to more quickly. Importantly, however, we failed to find any support for the hypothesis that concave targets are inherently more salient. We conclude that previous findings in the literature, which have been taken to indicate preferential processing of concavities, due to their increased salience, are more likely the result of an early computation of part structure based on concavities.